The software engineer removed the RFID chip from the Tesla Model 3 valet card using acetone, then placed it into a biopolymer, which was injected through a hollow needle into her left arm. A professional who specializes in body modifications performed the injection.
The original idea was to use the existing RFID implant chip that was already in her hand to be able to start the Model 3. That method, which would have involved taking the Java applet and writing it onto her own chip, didn’t work because of Tesla’s security.
Not the first time people implant chips in their body to access systems.
The idea of having multiple implants is not practical, even when they will become mainstream. It's much more efficient to have a single implant featuring an industry-backed (and hopefully open source) platform, uploading third-party apps on it as needed. Just like Amie DD wanted to do.